* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

.box {
    width: 600px;
    height: auto;
    margin: 20px auto;
    background-color: white;
}

h2,
p {
    text-align: center;
}

input {
    width: 50px;
    text-align: center;
}

table {
    width: 600px;
    margin: 10px 0;
    /* 合并表格边框 */
    border-collapse: collapse;
}

caption {
    /* 标题底部外边距 */
    margin-bottom: 8px;
    font-size: 20px;
    font-weight: bold;
}

th,
td {
    border: 1px solid #000000;
    /* 文本居中排列 */
    text-align: center;
    padding: 6px;
}

td[colspan="7"] {
    text-align: left;
}